Hydraulic valve gear



LQA. KAUFFMAN ET AL HYDRAULIC VALVE yGEAR Filed Jan. 18, 1929 Dec. 30.I

Patented Dec. 3i),l 1930 y l l l UNITED STATES PATENT f GFFICE LEROY A.KAUFFHND-WIIVWDSG IIDAVIS, 0F WASHINGTO, DISTRICT OF COLUMBIA,

v ASSIGNOBS T WARREN NOBLE, OF DETBOII, MIGHIGAN mamme vA'LvE emaApplication led January 1.8, 1929. Serial No. 333,455.

This invention lrelates to hydraulic vatlve ber immediately uponmovement of the actugears and has for its object to provide an atorplunger, this pressure will be transmitefficient gear composed of fewerparts than ted to the oil and a1r in the reservoir. If air any similargear heretofore proposed or built is present, then, it will compress.The plung- 5 and which will be cheaper to manufacture, er on furtheractuation may open an outlet -55 more reliable in operationv and freerthan from the reservoir releasing the pressure and usual from small andintricate parts which thereby allowing the air to vent.l usually renderthe proper assembly of such For starting purposes wherein a greatermechanisms beyond the skill of the 4poorer amount of air must be bledthan can be mechanics. y quickly accommodated bythe above described o Itis the specific object of this invention collecting means we proposetotake advanto provide an improved air bleedin mechatage of. certainfacts welll known to those nism for normal operation which is ee fromskilled in the art of handling uids under pressure sensitive valvesofthe daphram Ior pressure as in the use ofvbearings. It is well CheekValve type 01' any Other'smi'lal design known that lubricant or fluidcannot be faced 65 requiring individual bleed structures and yet betweentwo substantially contacting static Which Will function t0 eiliclelltlyCOllBCt and Surfaces, Thus in the case of bearmgs no bleed air.lubrication can be effected between the con- It is a further Object 0fthe invention 150 ltacting surfaces until rotation of one surface 2provide an air bleed which will not bleed liuld occurs-whereupon oil isdragged along and 70 fIOm the System unless ail' S PreSeIl,the1`eby a.film is provided between the surfaces. It redueng the IOdillglleeessary on the supply is further known that air cannot bedriven v mechanism and also materially reducing the through a film ofoi1 under pressure, Thus` 4. lkelhed 0f 10st mOtOD- there is no air inbearings although air g lt .lS a Still further Object 0f thelllveiltlOIl bubbles may have existedv in the 0i] prior t0 l5 to provideall allXlIy bleed mechanism feeding to the bearings. It is also, ofcourse, which muy be Considered un integr u1 Part 0f well known that aircan be forced through an the above described bleeding arrangement'extremely Small opening, Woproposo to take which will function to bleedair upon initial advantage of the above facts by providing a Charging 0fthe System with uuid and which vent at some point in our valve gear,prefers 73u,

autmatlcally beGOIIle4 lllOpeItlVe OI jfl- 0m the exact, region of airaccumula. further bleeding as quickly as thuystem be' tion or from thereservoir above described, comes lled with oil, the first describedbleed the'vent to carry a bu which will havev a I mg mechamsm thetal-img @are of all" auf very restricted limit of activity whereby itthereafter' will almost contact its seat when open and In carrymg themveptlon Into dieet we which/upon becoming wet will immediately mayprovlde a reservo for couectmg an' seal itself due to the fact that anoil film 4 the hydraulic chamber from the highest point air cannot Pass"By this'arrangement air 90 may be bled. freely until tllile syetenrfillted 't and is closed b a slid valve which with lubricant WueleuPOuP@Va Ve W1, au 0" iiizdyvbg comprised of ong,7 of thelungerscon- 'mutiauybecome luOPel'utlVe, tu@ System the ventionally employed as an open sideof the depeuulug for b leedlug 0ntu arrangement reservoir. As quickly asan impulse is impIeVlOllSly described. 95 posed on the actuator plunger'acari-,ain a Y A completeunderstanding of the invention amount ofliquid and any air present will be Wlll be had W1th reference to theaccompanydriven into the little reservoir, the slide will ing drawingswherein 17s illustrated, by way close and in view of the fact that'ressure of example and not in a limitmg sense, one

thereof ydur-ing periods oftpuppe't valve in- 'will have begun to risein the hydrauhcchamembodiment of our inventionas it may be '10er'carried into effect with an engine employing head camshaft 2 except forsuch modifications as' are necessary for conversion into a hydraulicvalve mechanism as will hereinafter become apparent, and 3 refers to apup- A* pet valve provided with the usual return spring 4.

The casing 1 is bored at 5 to receive a hollow plunger 6 which is ofless length than the depth of the hole 5. Extending through the casing 1is a second plunger 7 which may be the valve stem or an extensionthereof and which is providedwith a smooth upper end 8 fog snuglyfitting within plunger 6.

A fluid pressure supply line 9 which may be connected into theengine'lubricating system is led into the casing 1 and preferably inletsinto bore 5 'at or near the bottom thereof. A non-return check valve 10prevents backflow-into the line 9. As fluid enters the bore 5 from line9 it fills the space in the bottom thereof and passes through aggroove11 into the space between the plungers 6 and 8 which is hereinafterreferred to as the hydraulic chamber. Any air in the system will seekthe highest point thereof which,

in the example shown, is the top of plunger` 6. Leading from this regionof airaccumulation are passageways 12 which, when the plunger 6 is "innormal position as shown in Figure 1, are in communication with areservoir 13 herein shown as comprising an annular groove in the side ofcasing 1. Air collecting in the hydraulic chamber will be conducted onaccount of its buoyancy tothe reservoir 13 and as quickly as actuator 6receives impulse from cam 2 such air as may be collected in thereservoir will immediately be placed under pressure equal to the-pressure in the hydraulic chamber. -Very soon' after beginning. itsdownward motionit is readily seen that the passages 12 are disciinectedfrom communication with the reservoir 13 and the air under pressureremains in the reservoir until an outlet passageway 14 which is incontinuous cmmunicationwith the reservoir, is uncovered by the plunger6.

It is best that theoutlet of passageway 14 be uncovered immediatelyafter the closing of the communication rbetween the hydraulic chamberand the reservoirhas been effected,

as the pressure in the reservoir will nothave quickly as the outlet 14is uncovered the air ya hydrau ic ilui in the reservoir, being undercompression, will quickly esca e.

It is to be noted) that if no air is present, any oil which may bepresent in the reservoirlis substantially incompressible so that nobleeding would occur upon uncovering of the outlet passage 14 so that noloss of iuid would occur.

It is seen that such an arrangement will effectively remjove air insmall quantities as it collects, however, when it is desired toinitially fillthesystem such a device alone would not in itself functionto quickly relieve a long column of air in the conventional overhead tye of valve gear.

We, t erefore, provide a valve which will function to vent air but whichwillbecome inoperative for further bleeding lof oil or air as uickly asit shall have served its purpose. uch an arrangement is shown in thedrawings wherein a check valve 15 guards an outlet passageway 16 incommunication with the reservoir 13. The ball 15 is provided with aslight bit of play between its open or downward position and its seatedposition. The amount of travel allowed the ball should preferably beabout one and a half or two and a half thousandths of an inch. Theoperation is as follows: upon initially charging the system with oil airwill escape past the check valve until oil reaches the ball whereuponthe ,ball and its seat will become wet, a film of oil forming betweenthem. This hn forms an effective seal against further escape of oil orair as previously explained. As long asoil is present then the checkvalve will no longer function as a valve but will actas a seal foroutlet 16. As quickly as this valve shall become inoperative the outlet14 then stands ready to assume its normal duty as described. A spring 17may be rovidedlto hold ball 15 from its seat as it oes not need to se tto form a seal and this spring assures the b l1 being unseated at anytime lubricant is withdrawn or recedes from' 1. In a hydraulic valveOoperating mecha-v nism, an o eratin and an operated plunger, p chamberintermittently connected to a source of fluid supply, means outside ofsaid chamber for collecting air accumulating therein, means forcompressing air collected and means for releasing the j pressure wherebysaid air is vented. had suicient time to become dlssipate'd. As

2. In a hydraulic valve operating mechaa hydraulic chamber between saidplungers having a region of air accumulation therein,l a-source of fluidpressure supply Vfor replenishing fluid in said chamber, an 'aircollection y reservoir outside of said chamber adapted forrl connectionwith said region of air accumulation whereby air vin said system willfreely pass into said reservoir, the iiuid in said chamber acting tocompress the air in said reservoir upon a rise in pressure thereon,means comprising a valve for disrupting communication between saidreservoir and said hydraulic chamber after said air is compressed andmeans for releasing the pressure on said air whereby said air isp-ventedfrom said reservoir.v

3. In a hydraulic valve operating mechanism, an operatin and an operatedplunger, a hydraulic chamer between said plungers having a region of airaccumulation therein, a source of iuid pressure supply for replen--ishing fluid in said chamber, an air collection reservoir outside ofsaid chamber adapted for connection withpsaid region of air accumulationwhereby air in'said .system will freelyy ass into said reservoir duringpe- Y' riods o puppet valve inactivity, actuation of said operatingplunger to a small extent creating a. rise in pressure in said systemwhereby air in said reservoir is compressed, actuation of said .plungerto a greater extent closing communication between said region and saidreservoir whereby airis trapped in said reservoir under pressure,actuation of said plunger to a still greater extent uncovering Y apassageway to said reservoir 'to the atmos-n phere whereby said air isvented during periods ofpuppet valve actuation.

4. Ina hydraulic valve operating mechanis'm an operating and an operatedplunger a hydraulic Huid chamber between said plungerafmeans for ventingair upon m1- -tially charging said system with iiuid, said i meanslbecoming' inoperativeupon said system becomingl lled with fluid, andmeans for bleeding air from said system during normal operation.

5. In a hydraulic valve operating mechanism, an operating and anoperated plunger, a hydraulicfluid chamber having a-region` of airaccumulation therein between said .plungers, means for venting air fromsaid from' said region of air accumulation tiring periods of chargingsaid chamber with iiuid, said-means becoming inoperative A for furtherbleeding upon becoming wet with ,said `fluid, and means for bleeding airfrom said chamber during normal operation of said mechanism, said last'named means being inoperative to bleed fluid.

.6. In a hydraulic valve operating mechamsm, an'operating and anoperated plunger, a hydraulic fluid chamber having a region of -alraccumulation` therein between said plungergmeans for` venting air fromsaid

